Managing Postharvest Diseases of Apple and Pear in the Orchard and Storage

Transcription

1 Achour Amiri Washington state University Tree Fruit Research and Extension Center Managing Postharvest of Apple and Pear in the Orchard and Storage Fruit School-2017 Wenatchee, March 15, 2017

2 Blue Mold Gray Mold Bull s Eye Rot Postharvest of Tree Fruit More than 90 fungal species Speck Rot Sphaeropsis Yellow Rot Mucor Rot Trade issue complex disease

3 Blue Mold Penicillium expansum Penicillium sp. Typically postharvest Wound pathogen Soft and watery Profuse sporulation Sanitation: Rooms and bins Use of fungicides (conventional) postharvest Economic impact: ~$5 million

4 Gray Mold Botrytis cinerea Pre and postharvest (nesting) Latent infections Field sanitation: Key Conventional: use of fungicides pre- and postharvest High risk for resistance development

5 Bull s Eye Rot Neofabraea perennans (WA) N. Alba (OR), N. malicorticis, Cyptosporiopsis kienholzii Pre-harvest infections Cankers Latent infections (>4 months of storage) Wet pre-harvest conditions Orchard sanitation Quarantine: export problems (some species)

6 Speck Rot Phaciopicnys washingtonesis (Spek rot-apple) Phacidiopycnis piri (pear) Pre-harvest infections Crab apple pollinizers: source of inoculum Latent infections Weak/slow pathogen % of total decay (2005) Quarantine: Trade problems Orchard sanitation: key in organic/conventional

7 Yellow Rot Lambertella corni-marris Wound pathogen Preharvest infections? Inoculum source: unknown yet Latent infections First reported in 2015: 3-5 % of total decay Quarantine: export problems Conventional: Scholar and Penbotec effective

8 Apple Postharvest Occurrence in WA 2016 Others Sphaeropsis rot Yellow rot Speck rot Bull's eye rot Gray mold Blue mold Trade diseases 10 % Incidence (%)

9 Epidemiology and infection timing

10 Orchard selection Site Selection (new orchards) Sunny, well-aerated, Mid-high and well drained soil types Isolating large lots of trees (~1/2 mile): Hedges, neglected neighboring tree fruit. Planting Density: 800 to 1000 trees/ac, more spaced trees may have less diseases Rootstocks: Resistance known for fire blight & Phytophthora but not for storage rots Certified disease free plant material Weed management: important for young trees Avoid areas with history of replant disease

11 Host Management Cultivar Selection (new orchards) Storability vs. consumer demand? Basically: all mainstream cultivars can be infected by postharvest rots. Some cultivars: Gala, Honeycrisp, Fuji, Bosc (pear) more prone to rots No source of resistance to postharvest pathogens in current cultivars

12 Host Management Cultivar Susceptibility Disease severity index Cultivar Blue mold Gray mold Bull eye rot Mucor rot Epidermis strength Fuji Braeburn Golden Del Empire Jonagold Royal Gala Granny Smith High variability between seasons 2: lowest susceptibility; 6: highest susceptibility Spotts et al. 1999

13 Host Management Host resistance to postharvest diseases Wild apple: Malus sierversii (central Asia) Lines resistant to Penicillium expansum (Blue mold) Crosses are being made and tested for resistance and phenology (USDA-ARS-East Coast) Wild apple selection Long term objective: ~6-8 years Wisniewski et al. 2011

14 Host Management Balanced Mineral nutrition can mitigate diseases Mineral Nutrition Mineral Crop Pathogen Effect Nitrogen Grape Botrytis cinerea Increase Phosphorus Potassium Calcium Magnesium Apple Cabbage Grape Apple Pear Apple Poppy N. Malicorticis (Bull s eye rot) Botrytis cinerea Botrytis cinerea Alternaria sp. Colletotrichum sp. Botrytis cinerea Phialophora (Side rot) Replant disease Alternaria, Cladosporium Increase Decrease Decrease Decrease None Decrease Manganese - Several soil pathogens Decrease Zinc - Mycotoxin fungi: Penicillium, Aspergillus Decrease Copper - Serval pathogens Decrease Increase/Decrease ratio* * Ratio between the number of studies reporting increased effect/decreased effect

15 Infection vs. Disease (pathogen) Fungi (most) Bacteria (Fire blight, Bacterial canker) Viruses The Pathogen How to manipulate the pathogen? Exclusion: Certified plants (viruses, Phytophthora, Anthracnose, Nectria) Host Reduce dispersion: Drip irrigation, mulch Sanitation: preharvest (addressed) and postharvest Environment Disease Pathogen Apply the right biofungicides (if available) at the right time

16 Pre-harvest sanitation Orchard management Pathogen Management Gray mold Host Disease Environment Pathogen Mummies Cankers

17 Pre-harvest sanitation Pruning: Manchurian crab apple trees Pathogen Management Host Environment Disease Pathogen Sphaeropsis Phacidiopycnis Lambertella (Yellow rot)?

18 Pre-harvest sanitation Pruning: crab apple trees Unpruned Chainsaw Detailed Pathogen Management Incidence (%) Host 0 Orchard Phacidio infection Speck rot in storage Disease Environment Pathogen Kim et al. 2016, WTRC reports

19 Pre-harvest practices Overhead irrigation: can increase moisture Pathogen Management Host Disease Environment Pathogen

20 Pathogen Management Pre-harvest sanitation Leaves: Source of Botrytis, Nectria Leaf removal or decomposition Sugar beet vinasse sprays Host Disease Environment Pathogen

21 The Pathogen Field Bio-fungicides Fungicide Active ingredient Target Disease Actinovate AG DoubleNickel LC/55 Serenade OPTI/Max Neem products PureSpray Green GreenCure/Kalig reen/bi-carb Streptomyces lydicus WYEC 108* Bacillus amyloliquefaciens stain D474 Bacillus subtilis Strain QST 713 Hydrophobic Extract of Neem Oil Powdery Mildew Botrytis Based on label recommendations Mineral oil Fire Blight Powdery mildew Botrytis/Alternaria Powdery mildew Bitter Rot Bull s eye rot Botrytis P. Mildew Anthracnose Botrytis/Alternaria P. Mildew Botrytis On the Label* WSU has not tested these products Bicarbonates P. mildew Botrytis Copper products Copper Anthracnose Nectria On the label for pome fruit - Not on pome fruit label but reported on other crops PHI 0 0 0? 0 1 CL

22 Major problem for organic pome fruit Production: 3x increase in 3-5 years Management in Postharvest How to extend the shelf-life of larger volumes?

23 Harvest fruit at commercial maturity The Pathogen Management in Postharvest Over-ripe fruit are more susceptible

24 The Pathogen Room and bin sanitation is a key Penicillium (Blue mold) Cladosporium (Secondary pathogen) Bacteria/yeats Management in Postharvest Amiri et al. 2005

25 The Pathogen Room and bin sanitation is a key Inoculum size at start is crucial 5% Cultivar with high susceptibility Management in Postharvest 5% Cultivar with lower susceptibility Dutot et al

26 Room and bin sanitation is a key 5% The Pathogen Management in Postharvest 5% Empty rooms Amiri et al

27 The Pathogen Management in Postharvest Physical control Hot air: used in orchards/vineyards Quarantine method: several insect pests Thermotherapy: Heat air/hot Water (45-48C/ F for 2-30 min) Bull s eye / Alternaria / Nectria rots Gray mold (questionable) 5% Large volume and Sustainable energy costs?

28 Biological and alternative methods Biological: inconsistent efficacy & wet application May help for short-term storage The Pathogen Management in Postharvest Fungicide Active agent Agent type Available in USA Bio-Save Pseudomonas syringae Bacteria Boni Protect Aureobasidium pullulans Yeast - (new in Europe) Candifruit Candida sake Yeast - Nexy Candida oleophila Yeast - Natamycin (pimaricin): From Streptomyces natalensis Natacyn drug to treat eye fungal infections Food preservation Pace: working on the development Hope: sustainable mid/long term storage?

29 The Pathogen Management in Postharvest Other postharvest alternatives Method Benefits Limitations Commercial use UV-C Chemical elicitors Ozone Sulfur dioxide -Good sanitation -Induce host resistance -Enhance fruit resistance -Natural products -Gas or fog application -Cost sustainable -Additional applications during storage -Good efficacy against postharvest decay -Kills spores on surface -Lack or harmonization -Wet application -Unstable efficacy -Not all allowed in organic -Does not penetrate natural openings/wounds -Fruit injury risks -Sulphite residue /? (gas)

30 Ashour Amiri WSU-TFREC 1100 N. Western Ave. Wenatchee, Tel: Cell: Thank you